Rhyme natural in English.
31. It is natural to English poetry—i.e. Middle and Modern English, or English poetry proper—to rhyme; and, except in the case of blank verse, no unrhymed measure for the last seven centuries has ever produced large quantities of uniformly satisfactory quality.
It must be "full,"
32. Rhyme in English must be "full," i.e. consonantal (on the vowel and following consonant or consonants), not merely assonantal (on the vowel only). Assonance by itself is insufficient.
and not identical.
33. It should not, according to modern usage, be identical—that is to say, the rhyming syllables should not consist of exactly the same vowels and consonants. But exceptions to this may be found in good poets, especially when the words are not the same.
General rule as to it.
34. Good rhyme has necessarily varied, at different times, with pronunciation; but a certain rough rule may be seen prevailing not uncommonly, that vowels in rhyme may take the value which they have in words other than those actually employed.[29]
Alliteration.
35. What is sometimes called "head-rhyme" (i.e. "alliteration") has now no place in English as rhyme at all, nor does it constitute either metre or stanza; but it is a permissible, and often a very considerable, ornament to verse.